The third season is complete. The fourth is coming. Yet HBO’s Game of Thrones faces a potentially complicated future. Below Thrones showrunners, author George R.R. Martin and HBO’s programming president talk to EW about how the hit series might navigate the franchise’s uniquely twisting road ahead. “There is a ticking clock here,” says writer-executive producer David Benioff.

Sunday’s finale cut off the action roughly two-thirds of the way through George R.R. Martin’s third Ice and Fire novel, A Storm of Swords. There are two more books left unexplored (A Feast for Crows, A Dance With Dragons), which will present a few manageable adaptation challenges. Martin is working on his sixth book (The Winds of Winter) and plans a seventh (A Dream of Spring), but there’s no guarantee either will be ready in time for Thrones’ annual production schedule, or even that the seventh novel will be Martin’s last entry in the series.

Season four, at least, should be relatively straight-forward. Martin’s story provides a strong map for the near-term.

Adapting Feast is more tricky. While Book 3 is the runaway fan favorite of the Ice and Fire saga, Book 4 is considered the weakest. Feast included new characters and tangents while omitting some beloved names like Tyrion, Jon and Daenerys. Since the events in Book 5 largely overlap with Book 4, Thrones will start drawing heavily from both novels at the same time to maintain chronological consistency. Some elements of Book 4 could (and probably should) remain on the page for Thrones to continue effectively serving its sprawling universe of current storylines and characters.

“I don’t think we want to answer specifically what we’re keeping and dropping, but we do take your point,” Benioff said when asked about Book 4’s content. “The series has already reached a point where there are so many characters, particularly in season three we’re introducing so many new ones, we run the risk of bursting at the seams as we try to cram every single subplot and all the various characters and it becomes impossible on a budgetary level and it becomes impossible on an episode-basis to jump around every few minutes to 30 different characters and locations. We don’t want to do that, and recognize that as a real risk and we will take steps not to fall into that trap.”

Of greater concern is the pace of books vs. seasons. It’s an issue that fans pointed out from the moment the show was greenlit and now even HBO is beginning to realize there could be an issue. Book 5 took Martin six years to write and it was released in 2011. “I finally understand fans’ fear – which I didn’t a couple years ago: What if the storytelling catches up to the books?,” says HBO programming president Michael Lombardo. “Let’s all hope and pray that’s not going to be a problem”

Martin, for one, isn’t worried. The way the author sees it, producers have plenty of material to keep Thrones rolling. “I think the odds against that happening are very long,” Martin says when asked about the show catching up to his novels. “I still have a lead of several gigantic books. If they include everything in the books, I don’t think they’re going to catch up with me. If they do, we’ll have some interesting discussions.”

Martin points to Starz’ Spartacus, which interrupted its main storyline with a prequel season. As it so happens, Martin has discussed with HBO the possibility of developing a series based on his Hedge Knight books, which are prequels to Ice and Fire.

Yet HBO and Thrones producers are wary of stretching the series, for both monetary and creative reasons.